1. Field of the Invention
The present invention relates to a metallurgical furnace installation and particularly to the improvement of the drainage structures for discharging the melt remaining in the furnace when operations are suspended.
2. Prior Art
As schematically depicted in FIGS. 1 and 2, a continuous copper smelting installation comprised of a plurality of metallurgical furnaces is hitherto known. The smelting installation comprises a smelting furnace 1 for melting and oxidizing the copper concentrates supplied together with oxygen enriched air, to produce a mixture of matte M and slag S, a separating furnace 2 for separating the matte M from the slag S, a converter or converting furnace S for oxidizing the separated matte M into blister copper C and slag, and launders 4 for defining melt passageways to bring the furnaces into fluid communication with one another. The smelting furnace 1, the separating furnace 2 and the converting furnace 3 are arranged so as to be at different elevations in descending order, so that the melt flowing out from the outlet 5 of each furnace may be tapped via gravity through the launder 4. Furthermore, in each of the smelting furnace 1 and the converting furnace 3, lances 6 each composed of a double-pipe structure are inserted through the furnace roof and attached thereto to be vertically movable, and copper concentrates, oxygen enriched air, flux, cold charge, and so on are supplied into each furnace through these lances 6. The separating furnace 2 is an electric furnace equipped with electrodes 7. The blister copper C produced in the converting furnace 3 is transferred to anode furnaces (not shown) and is there refined into copper of higher purity.
In the smelting installation as described above, it is necessary to drain the melt remaining in the metallurgical furnace when operations are suspended for maintenance of the furnace. Therefore, the smelting furnace 1 or the converting furnace 3, for example, is provided with an openable and closable drain hole 8 to which a drain launder 9 is connected. Thus, the drain hole 8, which is kept closed during regular operation, is opened upon the suspension of the operation, whereby the melt remaining in the furnace is discharged through the drain hole and the launder. After being cooled and solidified, the discharge is granulated and recycled to the furnace through the lances 6.
Thus, in the conventional furnace installation, the melt drained from the metallurgical furnace must be appropriately treated before introducing it into the furnace again, and an excessive labor is required for this treatment. In addition, the generation of flue gas during the treatment of the melt may adversely affect the environment.